It has been 20 years since the appearance ofthe first commercial
lithium-ion batteries. A lithium-ion cell is comprised of four components,
i.e. a positive electrode, a negative electrode, a separator
membrane and an electrolyte. Among them, the separator is a thin
porous membrane which is placed between the positive and the
negative electrodes to avoid a direct contact (i.e. short-circuiting)
ofthe two electrodes. It allows free ionic transport butisolates electronic
flow. There are mainly three kinds of separators [1]including
micro-porous polymer membranes [2–4], non-woven fabric mats
[5–11] and inorganic composite membranes [12–18]. So far, the
separators used in commercial Li-ion batteries are nearly exclusively
micro-porous polymer membranes. But they are expensive
because the technology of manufacturing is currently controlled
by only several companies. The cost of the separator can be over
20% of the total cost of a lithium-ion battery. Therefore, it is importantto
find alternative, cheap and dependable membrane materials
to replace the current commercial separators in order to reduce
the cost of the lithium-ion batteries. In this paper, we attempt for
the first time to use a commercial rice paper (RP) as the separator
membrane in lithium-ion batteries.